High-Flow Air Filters™

The Last Air Filter Your Vehicle Will Ever Need

K&N® washable, reusable High-Flow Air Filters™ feature a state-of-the-art design of layered, oiled cotton media, engineered to improve airflow and capture contaminants—and designed to give you an increase in horsepower. Protect your engine with the filter that millions of drivers have trusted since 1969, from off-road to the on-ramp.

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The Original Red 201 Air Filter Since 1969

From the Racetrack to the Highway

There’s a reason top racers trust K&N® to protect their trophy trucks in the Baja 1000, premium racecars in 24 Hours of Le Mans, million-dollar NASCAR engines, and high-horsepower dragsters: K&N® air filters let airflow in, and keep dirt out. Designed for the racetrack—made for your vehicle.

Performance Tested

Each filter is tested for high-airflow and exceptional efficiency in a state-of-the-art ISO 5011 laboratory, to help ensure industry-leading protection.

Designed to Last

The durable filter frame and media is designed to last for the entire lifespan of your vehicle, and is protected by a 10-Year/Million Mile Limited Warranty.

Engineered for Airflow

Layered, oiled cotton media provides up to 50% more airflow than traditional paper air filters, which can provide an increase in horsepower.

Reduce Waste

Washable, reusable, and durable.

Explore the Benefits

Washable & Reusable

Unlike disposable filters which must be frequently replaced, K&N® High-Flow Air Filters™ are washable, reusable, and engineered to last for the life of your vehicle. Feel confident in your purchase with a 10-Year/Million Mile Limited Warranty.

Increase Performance

High-flow cotton media is designed to allow up to 50% more airflow than traditional paper filters—and greater airflow can result in increased horsepower and torque. K&N® air filters are tested on a SuperFlow flow bench to ensure increased airflow over a stock filter. View testing data for many K&N filters on individual product pages.

Reduce Waste

Over 100 million disposable air filters and their packaging waste end up in landfills each year. Choosing a washable, reusable product that lasts for the lifespan of your vehicle helps to reduce unnecessary waste.

INSTALLS EASILY

Engineered to fit easily into your factory air box as easily as any other air filter. Typically installs in less than five minutes with no tools necessary.

PROVEN FOR OVER 50 YEARS

Used in millions of cars worldwide since 1969, the original oiled filter design was created by Ken Johnson and Norm McDonald to meet the demands of rigorous off-road conditions. For over 50 years, the High-Flow Air Filter™ has provided high airflow rates and outstanding engine protection from dust, dirt, and other harmful engine contaminants for performance-minded drivers everywhere.

Protection Bundles

Now Available

“Absolutely love it, bike breathes so much better. Less lag on takeoff. It's amazing, AND I definitely noticed the HP gain when I get on the throttle. My bike went from an animal to a monster. Thanks K&N!”

K&N Air Filter

Terrence from Pennsylvania

Frequently Asked Questions

Not at all. Most disposable filters are "barrier filters”, which act as a physical barrier to dust particles. Once a dust particle covers a pore in the media, air can no longer flow through that space. K&N replacement air filters absorb dirt and dust particles instead of physically blocking them, allowing the pores in the material to continue to let airflow through.

K&N replacement air filters that fit into the factory air box can go up to 50,000 miles before cleaning is required, and large conical filters on a K&N air intake system can go up to 100,000 miles before needing to be cleaned, depending on your driving conditions.

We do not recommend using other detergents or solvents to clean your air filter, or other types of oil. Products other than those manufactured by K&N have not been tested and may deteriorate the performance and filtering ability of your air filter.

Never use a brush to dislodge dirt particles on your air filter. The bristles from a brush can rip and tear the filtering material on your air filter. K&N Power Kleen and K&N Synthetic Air Filter Cleaner are powerful degreasing detergents and will loosen even the toughest, most stubborn dirt particles with no scrubbing necessary.

First, determine what filtering material your air filter is built with by looking at the Product Specifications on the product details page for your air filter part number on the K&N website.

Synthetic air filters do not use any filter oil at all.

Most cotton air filters come from the factory pre-oiled and ready to install. Certain specialty and racing filters are manufactured as unoiled filters and will be clearly indicated as such. Check the Product Specifications on the product details page for your air filter on the K&N website to see if it requires oil.

If a tube of sealing grease was included with your air filter, the grease must be used during filter installation to ensure a good seal. Use only K&N sealing grease, or lithium-based grease as a substitute. Do not use petroleum based grease, as it may deteriorate the seal on your air filter.

K&N does not complete vehicle performance tests (dynamometer tests) for every application for which we build a replacement air filter. We do complete airflow testing for every air filter, and can verify that a K&N air filter will flow air with less restriction than its OEM counterpart. However, other components of the vehicle's air intake system (like the air filter housing or tubing) can create air restriction and limit horsepower. The design of these parts varies among different vehicles and manufacturers, so there is no way to estimate a certain amount of horsepower gain from just replacing an air filter. The higher airflow and lower restriction will increase performance, but we cannot guarantee a certain/exact amount.

No, an engine can only draw in a certain volume of air depending on the engine's bore and stroke, and the number of cylinders. A replacement air filter or performance intake system cannot physically increase the volume of air that the engine takes in.

No. This is an "urban myth" and has not been supported by any factual evidence. The oil does not come off of a K&N air filter when it is in use, even when over-oiled or in extreme air flow rates exceeding 1000 CFM.

If somehow K&N air filter oil were to make contact with a mass air sensor, the oil would not cause the sensor to fail. We have intentionally coated mass air sensors with our filter oil, and monitored the sensors' output when installed in daily driven vehicles. These sensors continued to function normally, even after being sprayed and submerged in K&N air filter oil. K&N air filter oil does not cause problems with mass air sensors. More mass air sensor information.

Automotive air filters are not rated by micron size, but are instead rated by efficiency. K&N tests the filtering ability of our air filters using the ISO 5011 test procedure. In general, most K&N air filters will test between 97%-99% efficiency. Some air filters have their air filter test data published in the Available Information section of the product details page for that part number.

We are unaware of any vehicle manufacturer having published specific filtration requirements for any of their vehicles. As per the rights guaranteed under the Magnuson-Moss Warranty Act, consumers are free to use any brand of replacement part in their vehicle without affecting the vehicle's warranty. Having specific filtration requirements would limit consumers' choices, and would not be viewed favorably by the Federal Trade Commission.

Not necessarily. 99% filtration efficiency is certainly a very good achievement. However, filter efficiency is just one statistic of filter performance which is measured (but is also the statistic most commonly published). The other air filter performance statistics measured are: capacity, restriction, and service life. These other factors reflect the amount of dirt the filter can hold, how easily air can flow through the filter, and how long the filter can be used before servicing. If one particular brand of filter consistently achieves 99%+ efficiency, it would be interesting to know if they also excel in the other performance areas, or are sacrificing one statistic to help increase another.

Given the fact that vehicle manufacturers do not publish specific filtration requirements for their vehicles, it is not strange that we find major, reputable filter brands offering replacement filters with efficiencies varying between 94%-99%. Many K&N filters achieve 98%-99% efficiency, in a product design that offers a longer service life and much lower restriction than other brands of filters. In short, a "better" air filter is really a judgement call, and varies by personal preference.

With over 6,000 individual part numbers available, there is a very good chance that K&N has an existing product to meet your filter needs. In the event we do not have an air filter available, you may look into the K&N Custom Filter Program, where we modify existing parts to meet customers' exact needs.

It is possible that the Check Engine Light may come on after installing a K&N air filter or performance intake system. This does not necessarily mean that there is something wrong with your air filter or intake; sometimes, the higher air flow and lower restriction provided by the K&N will uncover an existing mechanical or electronic issue with your vehicle. In rare cases, you may have a K&N product which was manufactured outside of its design tolerances, causing sensors in your vehicle to read data outside of their normal expected values. In either case, the K&N Warranty Department can work with you to narrow down the cause of the Check Engine Light and correct the issue.

K&N Has Your Back

K&N 10 Year/Million Mile Limited Warranty®

K&N auto filters are guaranteed to perform for up to 10 years or 1,000,000 miles without needing replacement. Visit the K&N Million Mile Limited Warranty page for more details.

Designed to Increase Horsepower

K&N automotive replacement air filters are designed to add horsepower and acceleration to your car or truck by providing up to 50% more air flow.

K&N History

K&N Filters has been designing and manufacturing performance air filters since 1969. K&N also makes thousands of racing and specialty type air filters and we are the #1 Filter in NASCAR®.